This invention relates to the formation and elimination of water or an equivalent compound and the resultant production of a metal alkoxide from a solution or suspension of particular metal compounds in a suitable polyhydric alcohol by a reaction initiated and maintained by the absorption of microwave radiation.
Examples of this invention are given by the formation of metal alkoxides of propanetriol (glycerolates) when particular compounds of these metallic elements such as zince or bismuth are mixed with or dissolved in glycerol and the resultant solution or suspension is irradiated by microwave energy of a suitable wavelength. The reactions involved may be exemplified by chemical equations showing the formation of zinc glycerolate (Zinc(1,2,3-propanetriolato(2-)-.quadrature.1, .quadrature.2) homopolymer, stereoisomer; C.sub.3 H.sub.6 O.sub.3 Zn) from a suspension of zinc hydroxide (or a solution of zinc acetate) in glycerol (propanetriol, C.sub.3 H.sub.8 O.sub.3): ##STR1##
A further example of the invention may be given by the formation of a new crystalline metal-organic compound, when, zinc hydroxide is reacted with the polyhydric alcohol sorbitol (CH.sub.2 OH--(CHOH).sub.4 --CH.sub.2 OH).
The invention is not limited to the compounds of these elements or to the alcohols glycerol and sorbitol but extends to and embraces any other element whose particular compounds may be reacted with a di-, tri-, or poly-hydric alcohol by these microwave techniques.
The high temperature formation of the glycerolates of zinc, cobalt, manganese and iron has already been described,
(1) Australian Journal of Chemistry vol. 23 no. 10, p1963 1971, Radoslovich, E. W., Raupach, M., Slade, P. G. and Taylor, R. M.
(2) Clays and Clay Minerals vol. 18 (1970), p53-62, Fuls, P. F., Rodrique, L. and Fripiat, J. J.
(3) Australian Journal of Chemistry vol. 36 (1983) p 1249-1253, Hambly, T. J. and Snow, M. R.
These reactions are achieved by the direct heating of particular oxides or hydroxides or other suitable compounds or salts of these metallic elements in the polyhydric alcohol, glycerol.
The pharmaceutical, cosmetic and various industrial applications of the zinc glycerolate, formed by the reaction of certain zinc compounds with glycerol at elevated temperatures, are the subjects of previous patents granted and applied for namely:
U.K. Letters Patent No. 2101132 May 15, 1985, R. M. Taylor and A. J. Brock.
Letters Patent France 81 21 914 Nov. 23, 1981, R. M. Taylor and A. J. Brock.
U.S. Pat. No. 4,544,761 Oct. 1, 1985, R. M. Taylor and A. J. Brock.